Means for fastening retaining rings on turbogenerator rotors



Fig].

Dec. 6, 1 932. ROSE 1,890,340

MEANS FOR ASTENING RETAINING RIN ROTORS GS ON TURBOGENERATOR Filed Sept. 20, .1959

r H /5 T M /6 INVENTOR Ben Afiose.

Patented Dec. 6,

A f UNITEDSTATAES PATENT OFFICE BENNIE A. Rosa, orwinxxNsisuno, PENNSYLVANIA, AssreNon T WESTINGHOUSE ELECTRIC &* MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA MEANSFOR FASTENING RETAINING RINGS, oN. TURBOGI'ENERATLOR no'rons Application filed September 20, 1930. Serial No. 433,255.

My invention relates to means for fastening telescopic parts so as to prevent relative axial movement, eventhoughthe parts are subjected to high temperature and/or speed,

and it has particular relationto means for fastening the retaining rings on the rotor bodies of turbo-generators.

Electrical engineers have always been confronted with the problem of producing a good means for supporting the retaining rings'which fit over the end turns of the rotor windings of turbine generators. At the high operating speed and over-speeds at which the machine must operate, the centrifugal forceron the ring and onthe field coilends produces quite a large expansion of the ring itself, which cannot always be avoided by tight shrinking of the retaining ring on the rotor body. V

It has been customary, heretofore, to provide hooks or annularshoulderson the telescoping portions of the retaining ring and the rotor body, respectively,,in order to prevent relative axial displacement at the highest over-speeds,but even this has not presented a sufliciently high factor of safety in some designs. This is particularly true when utilizing non-magneticretaining rings in order to reduce the losses of the machine, be-

causethe more suitable of such non-mag- "netic materials have a high thermal coefli cient of expansion, higher than that of brass, so that, if it is shrunk into place tight enough to withstand the highestover-speeds at the highest temperatures, it will require stresses too high for safety atstandstillwith the parts cold, because, if a little yielding were to occur in the ring material, the shrink fit would be-lostand the ring would be loose; According to my invention a new means for retaining the retaining ring is provided, comprising a ring whlch 1s shrunk onto the is shown in the 'accompany- Figure. 1 is a fragmentary longitudinal sectional view of a turbo-generator rotor member embodying my novel means for fastening' the retaining ring, and

Fig. 2 1s a transverse sectlonal new of I thesame on a in Figure 1. I

' My invention is shown applied to the r0- tor member of'a high speed dynamo-electric machine such as a turbo-generator, said rotor member comprising a body portion for carrying field windings, having coil-ends 6 which are restrained against centrifugal displacement by means of a retaining ring 8 a portion of which fits telescopically over a portion of the rotor body member, as indicated at 10. This. retaining ring may, or may not, be of a non-magneticmaterial having a very high thermal coefficient of expansion, higher than that of brass, such as the plane indicated byline II-II material described in Patent No. 1,574,782

granted March 2, 1926 to Erich Becker.

- The retaining ring is preferably shrunk onto the rotor body with a fit which is large enough. to give a: snugly fitting ring at the highest over speed and the highest operating temperature.

Associated with the retaining ring is a socalled end plate, which may or may not be of the. same material, and which is rigidly secured to the retaining ring by any suitable means, as. for instance, a shrink fit embodying interlocking hooks or shoulders at 12, in a manner similar to that heretofore utilized for fastening the retaining rings onto the rotor body.

" According to my invention, the retaining ring is held fromaxial displacement relative to the rotor body by means of a small wire 14, preferably of hardened steel, which is forced into corresponding or opposite grooves and 16, cut in the telescoping portions of the retaining ring and rotor body, respectively. l/Vhile I have shown, and prefer .to use, a round wire, I do not mean to exclude other possible cross-sectional shapes of thewire. .The wire 14 is introduced into the grooves 15 and 16 by means of a hole or perforation 17 drilled diagonally through the ring into the groove. The wire can be forced into the groove, the retaining ring being meanwhile held in place in a suitable press 7 (not shown). In case the wire cannot be forced substantially all of the way around I the circumference of the retaining ring, a number of holes may be utilized, with shorter pieces, of wire. r

The wire 14 is preferably provided with an enlarged head 18, having means 19 for withdrawing'the wire from the 'hole when it should become necessary to remove the retaining ring, the latter being first eased off of the wire by suitable heating and compression in a press (not shown). The head 18 normally fits into an enlarged counter-bore 21 in the open .end of the diagonal hole or perforation part having an approximately tangential perforation leading to said grooves, and a Wire extendingthrough said perforation and into said grooves, said perforation having a counterboard enlarged open end, and said wire having an enlarged head normally disposed in said counterbore and providing means for removing the wire;

In testimony whereof,'I have hereunto subscribed my name this th day of July, 1930.

BEN A. ROSE.

I It' will be observed that while I have illus- A, trated my invention in a preferred form of v embodiment, various changes and substitutions, maybe made without departing from the essential spirit and scope of my invention.

I desire, therefore, that the appended claims be given broadest construction consistent with their language andrthe prior art.

I I claim as my invention: r v 1. A high-speed dynamo-electric machine -,characterized by arotor having windings with coil-ends, solid'metal retainingrings for retaining said coil-ends against centrifugal forces, said retaining rings fitting telescopically over a portion of therotor member, the telescoped portions having opposite grooves, the retaining ring having an approximately tangential perforation I leading to said grooves, and a wire extending through said perforation and into'said grooves; 2. A high-speed dynamo-electric machine characterizedv by a rotor having windings with coil-ends, solid metal retaining rings I for retaining said coil-ends against centrifugal forces, said retaining rings fitting telescopically over a portion ofthe rotor member,

the telescoped portions having opposite grooves, the retaining ring having anapproximately tangential perforation leading to said grooves, and a wire extending through said perforation and into said grooves, said perforation having acounterbored enlarged open end, and said wire having anenlargedhead 1 l 'wire extending through said perforation and into said grooves, each groove being of a s ze to receive substantially one-half of-the wire.

4. A high-speed dynamo-electric machine e characterized by a rotor having two parts fitting telescopically together, the telescoped portionshaving opposite grooves, the outer 

